A novel attractant for Mexican fruit fly,Anastrepha ludens,from fermented host fruit

Chemicals from fermented chapote fruit were identified and evaluated as attractants for hungry adult Mexican fruit flies in laboratory and greenhouse bioassays. Twenty-eight chemicals identified from an attractive gas-chromatography fraction were as attractive as a chapote volatiles extract (CV) when mixed in the same amounts found in CV. Sixteen of the chemicals were slightly attractive to flies when tested individually. A mixture containing 15 of the chemicals by design and the 16th as an impurity, in arbitrary concentrations, was at least as attractive as the original CV. In a series of experiments, the number of chemicals was reduced to three by elimination of unnecessary components. The three-component mixture retained the attractiveness of the 15-component mixture. The three chemicals were 1,8-cineole, ethyl hexanoate, and hexanol (CEH). Attractiveness of the three-chemical mixture was equal to the sum of the attractiveness of the three individual components, suggesting that each chemical binds to a different receptor type that independently elicits partial attraction behavior. Optimal ratios were 1011 of the three chemicals, respectively. Optimal test quantities ranged between 0.4–4g of 1,8-cineole and 40–400 ng each of ethyl hexanoate and hexanol applied to filter paper in the laboratory bioassays. A neat 1011 mixture of the chemicals was 1.8 times more attractive than aqueous solutions ofTorula dried yeast and borax to starved 2-day-old flies when the lures were tested in competing McPhail traps in a large greenhouse cage.Diptera: Tephritidae.     

New Coumarin Derivatives and Other Constituents from the Stem Bark of Zanthoxylum avicennae: Effects on Neutrophil Pro-Inflammatory Responses

Three new coumarin derivatives, 8-formylalloxanthoxyletin (1), avicennone (2), and (Z)-avicennone (3), have been isolated from the stem bark of Zanthoxylum avicennae (Z. avicennae), together with 15 known compounds (4–18). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4, 9, 12, and 15 exhibited inhibition (half maximal inhibitory concentration (IC₅₀) values ≤7.65 µg/mL) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 2, 4, 8 and 9 inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤8.17 µg/mL. This investigation reveals bioactive isolates (especially 1, 2, 4, 8, 9, 12 and 15) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.     

Dermatitis-inducing furanocoumarins on leaf surfaces of eight species of Rutaceous and Umbelliferous plants

Eight species of Rutaceae or Umbelliferae, known to cause or suspected of causing photophytodermatitis, had the linear furanocoumarins psoralen, bergapten, and xanthotoxin on their leaf surfaces, in concentrations varying from 0.014 to 1800 /gmg/g fresh weight, equivalent to 0.17–56% of the total leaf concentration. The higher percentage generally observed for spring leaves compared to autumn leaves suggests a higher rate of transfer of these furanocoumarins to the surface in the younger leaves. Among the plants studied,Ruta graveolens had the highest surface concentrations of all three furanocoumarins. The relatively high effectiveness in causing dermatitis of some species with low surface concentrations may be explained by a more effective mechanism of transfer of the furanocoumarins to the skin. A role in the defense of the plant is suggested by their accumulation on the plant surface.A paper based on the work reported here was presented at the Groupe Polyphénols conference, Brock University, St. Catharines, Ontario, Canada, August 19–19, 1988.     

7种芸香科植物精油抑菌活性的研究

通过水蒸气蒸馏法提取了花椒、柠檬、脐橙、蜜柚、砂糖橘、丑柑以及椪柑7种芸香科植物的挥发性成分。采用肉汤稀释法测定了上述7种单种精油以及2组复配精油对金黄色葡萄球菌、表皮葡萄球菌、白色葡萄球菌、枯草芽孢杆菌等6种常见致病细菌的抑菌活性。结果表明,7种芸香科精油对金黄色葡萄球菌、表皮葡萄球菌、白色葡萄球菌、大肠杆菌、伤寒杆菌和枯草芽孢杆菌的生长均表现不同程度的抑制活性。除了丑柑精油外,其余6种精油对大肠杆菌均表现出了杀灭活性,MBC值在20~40mg/mL之间。精油按照不同比例复配后,抑制活性表现出差异性,柠檬与蜜柚或花椒精油存在拮抗作用。研究结果有助于了解单种精油和复方精油的抑菌性能,为芸香科植物精油的开发应用提供依据。     

Allelochemicals fromPilocarpus goudotianus leaves

The effect on germination, shoot, and root growth by bergapten, xanthotoxin, imperatorin, xanthyletin, xanthoxyletin, luvangetin, donatin and alloxanthoxyletol fromPilocarpus goudotianus leaves, onLactuca sativa var. nigra seedlings has been evaluated. A structure-activity correlation is discussed based on the bioassay results. Furanocoumarins appear to be the most active compounds in comparison with pyrano- and simple coumarins. The presence of an oxygenated function at C-8 decreases the germination effect in furano- and pyranocoumarins, while C-5 substituents do not cause significant changes on the activity.Part 2 in the series:Natural Product Models as Allelochemicals. For Part 1 see: Macíaset al. (1992).     

Insecticidal compounds from Phellodendron amurense active against Drosophila melanogaster

In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, the methanolic extract of the bark of Phellodendron amurense Rupr was found to show insecticidal activity against larvae of Drosophila melanogaster Meigen. Two alkaloids, berberine (1) and palmatine (2), were isolated by bioassay‐guided fractionation of the extract. Insecticidal activity against larvae of D melanogaster was demonstrated; 1 and 2 gave LC₅₀ values of 2.44 and 8.45 µmol ml^?1 diet respectively. Acute toxicity against adult D melanogaster was also found; 1 had the more potent activity, with an LD₅₀ value of 19.0 µg per adult. However, 2 had weak activity in this study. Therefore 1 was identified as an insecticidal compound from the bark of P amurense Rupr. © 2002 Society of Chemical Industry     

Lipid composition of murraya koenigii seed

Total seed lipids extracted fromMurraya koenigii (Linn), Rutaceae amounted to 4.4% of the dry seed. The total lipids consisted of 85.4% neutral lipids, 5.1% glycolipids and 9.5% phospholipids. Neutral lipids consisted of 73.9% triacylglycerols, 10.2% free fatty acids and small amounts of diacylglycerols, monoacylglycerols and sterols. At least five glycolipids and seven phospholipids were identified. Sterylglucoside and acylated sterylglucoside were major glycolipids, while digalactosyldiacylglycerol, monogalac-tosyldiacylglycerol and monogalactosylmonoacylglycerol were present in small quantities. The phospholipids consisted of phosphatidylethanolamine, phosphatidylcholine, lysophosphatidylethanolamine and lysophosphatidylcholine as major phospholipids and minor quantities of phosphatidylinositol, phosphatidylglycerol and phosphatidic acid. The fatty acid composition of these different neutral lipids, glycolipids and phospholipids were determined.     

Hydroxybenzoic Acid Derivatives in a Nonhost Rutaceous Plant, Orixa japonica, Deter Both Oviposition and Larval Feeding in a Rutaceae-Feeding Swallowtail Butterfly, Papilio xuthus L.

A Rutaceae-feeding swallowtail butterfly. Papilio xuthus L., feeds on various rutaceous plants but always rejects Orixa japonica Thunb. (Rutaceae). Females were strongly deterred from laying eggs by a methanolic extract of O. japonica leaves. Larvae also rejected a diet leaf medium impregnated with O. japonica leaf extracts. Several components in the water-soluble fraction of the leaf extract were found to deter both oviposition and feeding responses. Two major deterrent compounds were characterized as 5-[[2-O-(beta-D-apiofuranosyl)-beta-D-glucopyranosyl]oxy]-2-hydroxybenzoic acid and adisyringoyl aldaric acid. These compounds induced potent deterrence of both oviposition and larval feeding by P. xuthus, which suggests a congruent chemosensory mechanism of allomonal chemicals acting on both female tarsal chemoreceptors and larval maxillary taste receptors.     

A new method for fast isolation of insect antifeedant compounds from complex mixtures

Bioassay-guided isolation of bioactive natural substances requires monitoring of all fractionation and purification steps using a bioassay system. This is often a long and tedious process, especially with insect feeding bioassays. We report here a new method, based on the principle of bioautography, for a quick isolation of insect antifeedant compounds. TLC plates, after development, are coated with a thin layer of artificial diet and fed toSpodoptera litura larvae. The location of uneaten areas is then compared with theR _fvalues of the TLC spots, in order to determine rapidly the active fractions. This methods allows for a very fast determination of the most active antifeedant compounds in a complex mixture and considerably speeds up the isolation process. This new method was successfully applied in the study of antifeedant activity of several plant samples, and results are presented here for a model plant,Skimmia japonica (Rutaceae). Using this new method, the compounds responsible for the feeding-deterrent activity, three furanocoumarins (bergapten, xanthotoxin, and oxypeucedanin), were quickly and efficiently identified.